Camera shutter



CAMERA SHUTTER Filed Feb. 25, 1944 'l 2 Sheets-Sheet l CARL C FUERST ll@ f1 a lf Mr i945 c. c. FUERST 33252@ CAMERA SHUTTER Filed Feb. 25,1944 2 Sheets-Sheet 2 i n; J3 1 u25/20 55 F @J 60 CARL C FUERST INV TORA TTORNE YS Patented Aug. 14, 1945 UNITED STATES PATENT g OFFICE CAMERASHUTTER Carl C. Fuerst, Rochester, N. Y., asslxnor to Eastman KodakCompany, Rochester, N. Y., a corporation of New Jersey ApplicationFebruary 25, 1944, Serial No. 523,803

, for the fastest exposures and to provide a. shutter Claims.

This invention relates to a shutter for photographic cameras andparticularly to a shutter ol the type ln which a. master member is setor tensioned before an exposure can be made. One object of my inventionis to provide a shutter operating structure which is capable ofobtaining high-speed exposures. Another object oi my invention is toprovide a shutter mechanism in which accurately timed slow exposures canalso be obtained. A still i'urther object of my invention is to providea shutter blade driving structure in which the relation of the shutterblade driver can be altered 'with respect to the blade drivingmechanism. .A still iurther object of my invention is to provide amechanism including. a simple form of factory adjustment which can beused to facilitate assembling the shutter drive mechanism and otherobjects will appear from the following specication, the novel featuresbeing particularly pointed out in the claims at the end thereof.

In order to obtain relatively high-speed exposures with shutters oi thebetween-the-lens type, it has been necessary to drive they shutterblades with a high degree of rapidity causing the shutter blades to openand close as fast as possible. This can be most readily accomplishedwith shutter blades which are of the iso-called double-ended type: thatis, a shutter blade having opposite ends either one ot which may coveran exposure aperture in a shutter. Such shutter leaves can be movedfaster than shutter leaves which must open, reverse their direction ofmovement, and then close. i

It is also necessary to provide delayed action automatically timedexposures, such exposures usually ranging from Vone second to im or to1/200 of a second where the fastest exposures may be its@ to 1&0@ of asecond. In the slower-speed automatic exposures it is desirableto havethe shutter blades open, then to have the blades slow up or completelystop, then to have the blades close. With the double-endedftype of bladethe blade always moves in only one direction for opening and closing theexposure aperture. The delay or stoppage of the shutter blade in itsopen position is used to obtain the necessary delay for theautomatically timed exposure; as for instance, 1/5

or 1/2 of a second. It is customary to provide some retarding mechanismwhich comes into action during the period of time that the blades areopen.

It is therefore desirable to provide a shutterdriving mechanism inwhichthe drive causes an extremely rapid and continuous blade movement bladedrive in which there may be a dwell during that time that the exposureblades have uncovered the exposure opening.

My present invention is particularly directed to the provision of a,suitable drive with which both extremely high-speed exposures andexposures of the slower automatic variety may readily be obtained.

Coming now to the drawings wherein reference characters denote likeparts throughout:

Figure l. is a front elevation of a shutter mecham'sm including a driveconstructed in accordance with and embodying a preferred form of myinvention. In this figure, the parts are shown in position to makeanexposure, the shutter being set;

Figure 2 is a fragmentary view of the shutter shown in Figure 1 but withthe parts in the position they assume as the shutter is being set;

Figure 3 is a view similar to Figure l but with the parts of the shutterin the position they assume after an exposure has been made;

Figure 4 is a fragmentary plan View of a portion of the shuttermechanism with the driving lever set to a high speed driving position;

Figure 5 is a fragmentary detail sectional view taken on line 6-.5 ofFigure 3;

Figure 6 is a fragmentary detail perspective view of a portion of themaster member.

My invention consists broadly in a shutter mechanism in which aplurality of double-ended shutter blades carried by two movably mountedblade rings may be rapidly moved in a single direction for high-speedexposures and may be moved, stopped, and then moved again for producingdelayed action automatic exposures by a driving mechanism. This drivingmechanism may consist of a movable cam adapted to strike and move alever connected to the blade rings, there being a manual adjustment bywhich the relationship of the blade ring driving lever and the mastermember may be automatically altered as the shutter is set for ahigh-speed exposure.

More specifically, my invention may be embodied in the shutter shown inthe accompanying drawings. The shutter may include a generally circularcasing l, preferably provided with an upstanding flange 2 around itsperiphery, and an exposure aperture 3 in the center thereof. Theexposure aperture may be covered by a plurality of shutter leaves 4,each leaf 4 having broadenedout ends 5 adapted to cover the exposureaperture 3 and to exclude light therefrom. i

Each of the shutter leaves 4 is attached to each of two blade rings land 1, these blade rings being connected by means of a rocker arm 8which may turn about a pivot l. The rocker arm l has a pin i and slotconnection with each of the blade rings so that when the blade ring tmoves in a clockwise direction, the blade ring 1 may move in acounterclockwise direction.

Each shutter leaf 4 is carried by the two blade rings 8 and1 and theblades 4 may be pivotally attached, as indicated at I2, to one bladering and 10 may have a pin Il and slot |4 connection with the oppositeblade ring. This structure causes the blades to move rapidly when thepins I2 and I3 are moved in opposite directions by the blade rings 2 and1.

In order to move the blade rings, one of the blade rings here shown as 1is provided with an offset arm Il carrying a pin Il' which engages aslot I8 in one end |1 of a bell crank lever 8 which may be pivoted upona. stud i8. The opposite arm 20 of the bell crank lever is provided witha curved surface 2| constituting a cam follower. When the lever Il ismoved, the blade ring l will be moved, and when the blade ring is movedthe blade ring 1 will be moved in a substantially 25 equal and oppositedirection.

In order to move the lever Il,l I provide a master member which in thisinstance consists of a ring 22 mounted to turn in a. groove `23 formedin a mechanism plate 24 as best shown in Figure 30 5. -The ring 22 maybeprovided with a setting lever 25 which, as best shown in Figure 5, mayextend out through a slot 2B in the upstanding flange 2. Referring toFigure 6, the master member 22 is provided with a cam 21 which includes35 a pair of spaced inclined surfaces 28 and 29 connected by a surface30 which may be concentric with the shutter.

With the parts in the position shown in Figure 1, the cam follower 2|lies in front of the inclined 40 surface 28 so that when the `ring 22moves, the cam follower is raised and the lever i8 is turned about thestud I8. The parts are so positioned that the inclined surface 28 of thecam is suiiicient to cause the blades to move to an open position andthey will pause in this position as the master member moves theconcentric portion 3U of the cam beneath the cam follower 2|. Afterpausing normally, the inclined surface 29 moves the lever i8 stillfurther and causes this lever to 50 close the shutter blades. It shouldbe noticed that the inclined surfaces 2l and 29 are in the samedirection so that when the master member moves from its Figure lposition to its Figure 3 position, the lever i8 is always moved in thesame 55 direction; that is, in a counterclockwise direction with respectto these figures about the stud i9.

The master member 22 may be held in its set or latched position ofFigure l in the following manner:

The ring 22 is provided with an upstanding lug 32 which may be engagedby a latch element 33 carried by a trigger 34 pivoted on the stud 35 andpressed by a spring 38 into engagement with the lug 32.' Thus, the lug32 and the hook 33 forni 65 latch elements which will retain the mastermember 22 in its set position with the driving spring 31 under-tension.This driving spring may be attached to the mechanism plate 24 by a pin3B and may be attached to the ring 22 by means of 70 a pin 39. Thespring 31 always tends to turn the master member 22 in acounterclockwise direction. With the parts in the Figure l position anex posure may be made by depressingthe trigger 34, turning it in acounterclockwise direction releas- 75 :,aeacaa.

ing the latch elements 32 and 33. The spring I1 will rapidly move themaster member and cause the shutter blades to open and close as the cam21 engages the cam follower 2|.

The master member 22 carries a pin |22 which supports a leaf spring |23having its free end engaging a pin |24 carried by the blade ring 1.Blade rings 5 and 1 are connected by the rocker arm il to move inopposite directions and, since blade ring 8 carries a pin lli' engagingone end |1 of a bell crank lever IB, the pressure of spring |23 on -pin|24 tends to rock the bell crank lever il so that the end thereof 2| mayengage the cam 21-that is either the cam surface 23 or the cam surface29.

Since the extent of movement of the master member 22 is considerablygreater than the extent of movement of the blade ring 1 and since theymove in the same direction in making an exposure the pressure exerted byspring |22 on spring |24 becomes progressively less when the parts movefrom the Fig. 1 position to the Fig. 3 position. Consequently the spring23 does not tend tn react against the master member spring l1.

The above described exposure is used for the slow or automatic exposuressince the blades pause in their open position as the com follower 2|lies on portion 2|) of the cam. At this point, any suitable geardelaying mechanism may be connected to the shutter driving mechanism.

Where the highest speed is required, the relation between the camfollower 2| and the driving cam 21 is altered in such c. manner that`the cam follower does not engage the first inclined surface 2B at all,but is only engaged by the inclined surface 29. This movement isaccomplished by shifting the position of the stud i9 carrying the leveri8. This stud, as indicated in Figures 4 and 5, is positioned to engagea cam surface til carried by a plate 4| which is connected as by a screw42 to a speed adjusting ring d3 on the outside of the shutter casing l.When in the position shown in Figure 4, movement of the stud ifi ispermitted because this stud is supported on the end of a link 44pvotally attached at 55 to the mechanism plate 24. A spring 51 tends toturn the link 44 in a counterclockwise direction which movement isopposed by the cam 4D. When the parts are in the position shown inFigure 4, it will be obvious that when the trigger is released, themaster member will turn rapidly until the inclined surface 29 strikesthe cam follower 2l causing it to move. This time the cam follower liesabove and therefore fails to contact with either the first in clinedsurface 28 or the concentric surface 30 of the cam 2l. Consequently,when the inclined surface 29 strikes the cam follower 2|, it moves itrapidly through its fuli extent of movement causing the lever I8 to openand close the blades in one continuous rapid movement.

When the slower speed exposures are required, the cam. 40 may be movedin a counterclockwlse direction with respect to Figure l so that thestud i9 may move toward the center of the shutter because of the cut-outporti-on 5B of the cam 40. The movement of the link 44 will then belimited by the lug 5g striking the cam stop 60.

The cam stop S0 is a simple form of factory adjustment to insure theproper relationship between the Stud i9 and :the cam 21. When theshutter is being assembled, an operator may turn the cam 60 through theslot El so that the cam follower 2l will strike the inclined surface 2B,will ride over the concentric surface 30, and will strike rthe inclinedsurface 29 when the parts are adjusted to their Figure 3 position, andso that the cam follower 2l may miss the inclined surface 28 and theconcentric surface 30 when the shutter is adjusted for high speeds asshown in` Figure 4. In the present embodiment of my invention as shownin Figure 6, the .cam 21 may be attached to the master member 22 byrivets 83 or by any other suitable means which will hold the cam rigidlyin position.

In shutters of the type using double-ended blades as above described, itis necessary to cover the exposure aperture 3 during the time theshutter blades are opened and closed for setting the shutter. This maybe done in the manner shown in Figures l and 2 with supplementaryshutter blades if desired. This structure is the subject matter of my`copending application, Serial No. 489,484, for Camera shutter, filedJune 3, 1943. If it is desired to combine the diaphragm and thesupplemental shutter leaves, the structure used in my copendingapplication, Serial No. 489,485 for Diaphragm shutter; filed June 3,1943, may be employed.

In the rst-described supplementary shutter leaf structure there may betwo or more leaves movable to close the exposure aperture 3 before theshutter leaves 4 open and close during the setting operation. Asindicated in Figure 2, the supplemental shutter leaves and 1I may bepivotally attached to studs 12 and 13 as shown in Figure l. There may bea pin 14 and slot 15 connection between these leaves so that by rockingthe pin 'i4 to and from the center of the shutter, the supplementaryblades 10 and 1I may open and close. A spring 16 attached to apin ilnormally hold these blades in their open position. However, with theshutter parts in the rest position of Figure 3 and with the blades 10and 1i open, movement of the setting lever 25 to tension the mastermember spring 31 causes the hinged latch member 80, carried on the pin8l by .the master member 22, to engage the pin 14 moving this pin towardthe center of the shutter during the first part of the movement of .thesetting lever 25. This quickly moves the leaves 10 and 1I to the closedposition of Figure 2 so that the shutter leaves 4 may open and closeduring .the setting operation. This opening and closing takes placebehind the closed leaves 10 and 1I and consequently, light cannot enterthe exposure aperture 3. After the pin 1S rides up on the cam end of thelatch 80, it may ride around the concentric portion 83 of this latchuntil it slips off the end of :the latch. This occurs when the settingof lever 25 is complete.

f When an exposure is made by depressing the trigger 34, the mastermember again moves rapidly and the pin 14 rides on the inside of thelatch 8 causing it .to slip around the pin and into its Figure 3position at the completion of the exposure. The parts are now in aposition for setting the shutter again.

With the construction above described, the levier which operates theblade rings can be readily moved between a high-speed position and aposition for slow automatically timed exposures. This is accomplishedautomatically by merely turning the speed dial 43 which automaticallymoves the cam 40 to either the Figure 4 position for high-speedexposures or to the Figure 1 position for the more normal and slow-speedexposures. The length of the slot I6 in which the pin i5' may slide issuiliciently long to permit this movement of the lever I8 withoutdisengaging the pin Il' from the slot IB. The master member driving cam21 is a one-piece rigid member, the position of which cannot be alteredwith respect to the master member. Consequently, there are very fewmovable parts in thisdriving connection to get out of order, and theconstruction is quite simple. Since at high speeds, the shutter bladesare driven in only one direction by a. single inclined surface 29 on thecam 21, 'the action is deiinite and the exposures can be yreadilyduplicated.

While it is obvious that my invention is not conilned to the particular'form of parts shown and described because various modications willreadily suggest themselves to .those skilled in .the ant, I havenevertheless described a preferred form of an adjustable shutter drivingmechanism. I consider as within the scope of my invention all such formsas may come within the scope of the appended claims.

I claim:

l. In asihutter for photographic cameras of the type including a casing,a master member movablyy mounted in the casing, a trigger, elements forholding the master member in a set position, one of said elements beingoperable with the trigger to release the master'member for an exposure,double ended shutter blades, and at least one blade ring for moving theshutter blades, the combination with said master member, release meansand trigger, of a cam carried by said master member for operating theshutter blades, a bell crank lever, a movable mount therefor, toposition one end oi? the bell crank lever relative to the cam wherebythe point of impact by the cam driven by the master member against thebell crank lever` may be varied, and connections between the bell cranklever and said blade ring for transmitting movement from the bell cranklever thereto.

2. A photographic shutter comprising a plurality of shutter bladeshaving two ends adapted to swing in one direction only to rst open thenclose an exposure aperture; movable operating means for the shutterblades, a swingable cam, a master member carrying said cam, and aswingable bell crank lever having one end lying in the path of theswingable cam, and the other arm operably connected to the movableoperating means for the shutter blades, whereby said cam may engage anddrive the bell crank lever to first open and then close the exposureaperture moving the blades in one direction only, and an adjustablemember for altering 4the pivotal support of the bell crank lever and thepoint of contact of the bell crank lever and its driving cam.

3. In a shutter for photographic cameras of thetype including a casing,a master member movably mounted in the casing,l a trigger, elements forholding the master member in a set position, one of said elements beingoperable with the trigger to release the master member for an exposure,double ended shutter blades, and at least one blade ring for moving theshutter blades, the combination with said master member, release meansand trigger, of a cam carried by said master member for operating theshutter blades, said cam comprising two inclined surfaces both slantingin the same direction and spaced by an arcuate surface, a bell cranklever having two arms, one for driving said blade ring and the other forengaging the cam, and means for moving the bell crank lever pivot tolvary the contact position of the cam engaging arm of the bell cranklever and the said cam.

4. In a shutter for photographic cameras of the type including a casing,a master member movably mounted in the casing, a trigger, elements torholding the master member in a set position, one of said elements beingoperable with the trigger to release the master member for an exposure,double ended shutter blades, and at least one blade ring for moving theshutter blades, the combination with said master member, release meansand trigger, of a cam carried by said master member for operating theshutter blades, said cam comprising two inclined surfaces both slantingin the same direction and spaced by an arcuate surface, a bell cranklever `having two arms. one for driving said blade ring and the otherfor engaging the cam, and means for moving the bell crank lever pivot tovary the contact position of the cam engaging arm of the bell cranklever and the said cam, the arm of the bell crank lever for driving saidblade ring including a. pin and slot connection with the blade ring ofat least as great extent as the possible movement of the means formoving bell crank lever, whereby said bell crank lever arm and saidblade ring may always remain in operative engagement.

5. In a shutter for photographic cameras of the type including a casing,a master member movably mounted in the casing, a trigger, elements forholding the master member in a set position, one of said elements beingoperable with the trigger to release the master member for an exposure,double ended shutter blades, and at least one blade ring for moving theshutter blades, the combination wtih said master member, release meansand trigger, of a cam carried by said master member for operating theshutter blades, a bell crank lever, an arm on the bell crank lever to beengaged by the cam, said cam including cam surfaces for successivelyengaging and driving the bell crank lever in the same direction to openand close the shutter leaves, and means between the bell crank lever andsaid blade ring for driving the latter b'y the former.

6. In ashutter for photographic cameras of the type including a casing,a master member movably mounted in the casing, a trigger, elements forholding the master member in a set position, one of said elements beingoperable with the trigger to release the master member for an exposure,double ended shutter blades, and at least one blade ring for moving theshutter blades, the combination with said master member, release meansand trigger, of a cam carried by said master member for operating theshutter blades, a bell crank lever, an arm on the bell crank lever to beengaged by the cam, said cam including ca'm surfaces for successivelyengaging and driving the bell crank lever in the same direction to openand close the shutter leaves, and means between the bell crank lever andsaid blade ring for driving the latter by the former, and a supplementalmember carried by the master member for holding the bell crank leveragainst said cam.

7. In a shutter for photographic cameras of the type including a casing,a master member movably mounted in the casing, a trigger, cooperatingelements for holding the master member in a set position, one of saidelements being operable with the trigger to release the master memberfor an exposure, double ended shutter lblades, two blade rings movablycarrying the shutter blades, the combination. with said master memberand a blade ring, a cam and cam follower for moving the latter by theformer, of a spring carried by the master member and engaging a bladering for holding the cam and cam follower in contact, said blade ringand master member both being mounted. to move in the same direction inmaking an exposure, and mechanism for driving the master member.

8. In a shutter for photographic cameras of the type including a casing,an aperture therein through which exposures are made, the combinationwith said casing, of a plurality oi.' shutter leaves adapted to coverand uncover said exposure opening, three movably mounted concentricrings extending about said aperture, two of said rings carrying saidshutter blades and constituting blade rings, the third ring being springdriven in one direction and constituting a master member, a cam xedlymounted on the master member and including two similarly disposedinclined surfaces extending in the same general direction and connectedby a substantially circumferential surface, connecting means between theblade rings to move one ring in. one direction and the other in anopposite direction, a pivotally mounted cam engaging lever operativelyengaging a blade ring for moving the blade rings from the master member,and means for shifting the pivotal mount of the blade ring drivinglever.

9. In a shutter for photographic cameras of the type including a casing,an aperture therein through which exposures are made, the combinationwith said casing, of a plurality of shutter leaves adapted to cover anduncover said exposureA opening, three movably mounted concentric ringsextending about said aperture, two of said rings carrying said shutterblades and constituting' blade rings, the third ring being spring drivenin one direction and constituting a, master member, a cam fixedlymounted on the master member and including two similarly disposedinclined surfaces ex-tending in the same general direction and connectedby a substantially circumferential surface, connecting means between theblade rings to move one ring in one direction and the other in anopposite direction, a pivotally mounted cam engaging lever operativelyengaging a blade ring for moving the blade rings from the 'mastermember, and means for shifting the pivotal mount of the blade ringdriving lever comprising a pivoted link carrying the pivotal mount ofsaid lever, said means for shifting the pivotal mount of the blade ringdriving lever including a manually settable member carried by theshutter.

10. In a shutter for photographic cameras of the type including acasing, an aperture therein through which-exposures are made, thecombination with said casing, of a plurality of shutter leaves adaptedto cover and uncover said exposure opening, three movably mountedconcentric rings extending about said aperture, two of said ringscarrying said shutter blades and constituting blade rings, the thirdring being spring driven in one direction and constituting a mastermember, a cam xedly mounted on the master member and including twosimilarly disposed inclined surfaces extending in the same generaldirection and connected by a substantially circumferential surface,connecting means between the blade rings to move one ring in one theblade ring by point of engagement between said cam on the master memberand the cam follower, the length of said pin and slot connection betweenthe bell crank lever and blade ring being of an exi tent greater thanthe possible movement of said link..

CARL C. FUERST,

